(1) Field of the Invention
The present invention relates to a wiring board and a mounting structure using the same used in electronic devices such as various types of audio visual devices, household electric appliances, communication devices, computer devices, and peripheral devices thereof.
(2) Description of the Related Art
Conventionally, a structure in which an electronic component is mounted on a wiring board is used as a mounting structure in an electronic device.
Regarding the wiring board, Japanese Unexamined Patent Publication No. 2006-324642 discloses a wiring board in which a through hole is formed by drilling in a core substrate having glass cloth impregnated with an insulating resin, and a through hole via (through hole conductor) made of Cu or the like is formed on a side wall of the through hole by plating.
Further, Japanese Unexamined Patent Publication No. 2003-209359 discloses a wiring board in which a through hole is formed by laser processing in a core substrate having epoxy resin or the like reinforced by glass cloth, and conductive paste is filled in the through hole.
Incidentally, separation may be caused between glass cloth and a resin in a core substrate. In such a case, when a voltage is applied to a through hole conductor, part of the through hole conductor which is ionized by the voltage infiltrates into the separated portion (ion migration), and adjacent through hole conductors may make a short circuit. Accordingly, the electrical reliability of the wiring board tends to be decreased.